Intraoperative Pachymetric Measurements during Corneal Collagen Cross-Linking with Riboflavin and Ultraviolet A Irradiation
Received 16 April 2009; received in revised form 10 September 2009; accepted 11 September 2009. published online 22 October 2009.
Objective
To study central corneal pachymetric variations during corneal collagen cross-linking (CXL) treatment with the use of riboflavin and ultraviolet A irradiation (UVA).
Fifteen keratoconic patients (19 eyes) were enrolled.
Methods
All patients underwent riboflavin-UVA–induced corneal CXL. Intraoperative central corneal thickness (CCT) measurements using ultrasound pachymetry were performed during the procedure. Measurements were obtained after epithelial removal, after riboflavin drop instillation, and every 5 minutes (6 interval times) during UVA irradiation (30 minutes).
Main Outcome Measures
Central corneal thickness measurements.
Results
Mean patient age was 26.9±6.5 years (range, 17–40 years). Ten were male and 5 were female. Mean preoperative CCT was 458.5±21.5 μm (range, 427–494 μm; 95% confidence interval [CI], 448–467 μm) and 415.7±20.6 μm (range, 400–468 μm; 95% CI, 406–426 μm) before and after epithelial removal, respectively. There was a statistically significant decrease (mean, 75 μm) of CCT between the epithelial removal interval (415.7±20.6 μm; range, 400–468 μm) and at the end of riboflavin solution instillation (340.7±22.9 μm; range, 292–386 μm; P<0.001). There was no statistically significant change in CCT during irradiation (P>0.05). There was no statistically significant difference between preoperative and 1-month postoperative endothelial cell count (preoperative, 2780±197 to 1-month postoperative, 2713±116; P = 0.14). No intraoperative, early postoperative, or late postoperative complications were observed in this patient series.
Conclusions
During corneal CXL with the use of riboflavin and UVA irradiation, a statistically significant decrease of CCT was demonstrated.
Financial Disclosure(s)
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Institute of Vision and Optics University of Crete, Heraklion, Crete, Greece
Correspondence: Dimitra M. Portaliou, MD, Institute of Vision and Optics (IVO), University of Crete, Medical School, 71003 Heraklion, Crete, Greece
Available online: October 22, 2009.
Manuscript no. 2009-526.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Dr. George D. Kymionis was supported by a grant from the Hellenic Society of Intraocular Implant and Refractive Surgery.
ABSTRACT